feat(run/chat): add Markdown rendering

Signed-off-by: Dorin Geman <[email protected]>

Author: doringeman

commands/run.go

@@ -8,9 +8,11 @@ import (
 	"os"
 	"strings"
 
+	"github.com/charmbracelet/glamour"
 	"github.com/docker/model-cli/commands/completion"
 	"github.com/docker/model-cli/desktop"
 	"github.com/spf13/cobra"
+	"golang.org/x/term"
 )
 
 // readMultilineInput reads input from stdin, supporting both single-line and multiline input.
@@ -78,6 +80,75 @@ func readMultilineInput(cmd *cobra.Command, scanner *bufio.Scanner) (string, err
 	return multilineInput.String(), nil
 }
 
+var (
+	markdownRenderer *glamour.TermRenderer
+	lastWidth        int
+)
+
+// getTerminalWidth returns the terminal width, with a fallback to 80.
+func getTerminalWidth() int {
+	width, _, err := term.GetSize(int(os.Stdout.Fd()))
+	if err != nil {
+		return 80
+	}
+	return width
+}
+
+// getMarkdownRenderer returns a markdown renderer, recreating it if terminal width changed.
+func getMarkdownRenderer() (*glamour.TermRenderer, error) {
+	currentWidth := getTerminalWidth()
+
+	// Recreate if width changed or renderer doesn't exist.
+	if markdownRenderer == nil || currentWidth != lastWidth {
+		r, err := glamour.NewTermRenderer(
+			glamour.WithAutoStyle(),
+			glamour.WithWordWrap(currentWidth),
+		)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create markdown renderer: %w", err)
+		}
+		markdownRenderer = r
+		lastWidth = currentWidth
+	}
+
+	return markdownRenderer, nil
+}
+
+func renderMarkdown(content string) (string, error) {
+	r, err := getMarkdownRenderer()
+	if err != nil {
+		return "", fmt.Errorf("failed to create markdown renderer: %w", err)
+	}
+
+	rendered, err := r.Render(content)
+	if err != nil {
+		return "", fmt.Errorf("failed to render markdown: %w", err)
+	}
+
+	return rendered, nil
+}
+
+// chatWithMarkdown performs chat and renders the response as Markdown.
+func chatWithMarkdown(cmd *cobra.Command, client *desktop.Client, backend, model, prompt, apiKey string) error {
+	response, err := client.Chat(backend, model, prompt, apiKey)
+	if err != nil {
+		return err
+	}
+
+	// Try to render as Markdown, fallback to plain text if it fails.
+	rendered, err := renderMarkdown(response)
+	if err != nil {
+		if debug, _ := cmd.Flags().GetBool("debug"); debug {
+			cmd.PrintErrln(err)
+		}
+		cmd.Print(response)
+		return nil
+	}
+
+	cmd.Print(rendered)
+	return nil
+}
+
 func newRunCmd() *cobra.Command {
 	var debug bool
 	var backend string
@@ -103,8 +174,8 @@ func newRunCmd() *cobra.Command {
 
 			model := args[0]
 			prompt := ""
-			args_len := len(args)
-			if args_len > 1 {
+			argsLen := len(args)
+			if argsLen > 1 {
 				prompt = strings.Join(args[1:], " ")
 			}
 
@@ -149,7 +220,7 @@ func newRunCmd() *cobra.Command {
 			}
 
 			if prompt != "" {
-				if err := desktopClient.Chat(backend, model, prompt, apiKey); err != nil {
+				if err := chatWithMarkdown(cmd, desktopClient, backend, model, prompt, apiKey); err != nil {
 					return handleClientError(err, "Failed to generate a response")
 				}
 				cmd.Println()
@@ -178,7 +249,7 @@ func newRunCmd() *cobra.Command {
 					continue
 				}
 
-				if err := desktopClient.Chat(backend, model, userInput, apiKey); err != nil {
+				if err := chatWithMarkdown(cmd, desktopClient, backend, model, userInput, apiKey); err != nil {
 					cmd.PrintErr(handleClientError(err, "Failed to generate a response"))
 					continue
 				}

desktop/desktop.go

@@ -19,7 +19,6 @@ import (
 	"github.com/docker/model-runner/pkg/inference"
 	dmrm "github.com/docker/model-runner/pkg/inference/models"
 	"github.com/docker/model-runner/pkg/inference/scheduling"
-	"github.com/fatih/color"
 	"github.com/pkg/errors"
 	"go.opentelemetry.io/otel"
 )
@@ -364,15 +363,8 @@ func (c *Client) fullModelID(id string) (string, error) {
 	return "", fmt.Errorf("model with ID %s not found", id)
 }
 
-type chatPrinterState int
-
-const (
-	chatPrinterNone chatPrinterState = iota
-	chatPrinterContent
-	chatPrinterReasoning
-)
-
-func (c *Client) Chat(backend, model, prompt, apiKey string) error {
+// Chat performs a chat request and returns the response content.
+func (c *Client) Chat(backend, model, prompt, apiKey string) (string, error) {
 	model = normalizeHuggingFaceModelName(model)
 	if !strings.Contains(strings.Trim(model, "/"), "/") {
 		// Do an extra API call to check if the model parameter isn't a model ID.
@@ -394,7 +386,7 @@ func (c *Client) Chat(backend, model, prompt, apiKey string) error {
 
 	jsonData, err := json.Marshal(reqBody)
 	if err != nil {
-		return fmt.Errorf("error marshaling request: %w", err)
+		return "", fmt.Errorf("error marshaling request: %w", err)
 	}
 
 	var completionsPath string
@@ -412,17 +404,17 @@ func (c *Client) Chat(backend, model, prompt, apiKey string) error {
 		apiKey,
 	)
 	if err != nil {
-		return c.handleQueryError(err, completionsPath)
+		return "", c.handleQueryError(err, completionsPath)
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(resp.Body)
-		return fmt.Errorf("error response: status=%d body=%s", resp.StatusCode, body)
+		return "", fmt.Errorf("error response: status=%d body=%s", resp.StatusCode, body)
 	}
 
-	printerState := chatPrinterNone
-	reasoningFmt := color.New(color.FgWhite).Add(color.Italic)
+	var responseContent strings.Builder
+	var reasoningContent strings.Builder
 	scanner := bufio.NewScanner(resp.Body)
 	for scanner.Scan() {
 		line := scanner.Text()
@@ -442,37 +434,33 @@ func (c *Client) Chat(backend, model, prompt, apiKey string) error {
 
 		var streamResp OpenAIChatResponse
 		if err := json.Unmarshal([]byte(data), &streamResp); err != nil {
-			return fmt.Errorf("error parsing stream response: %w", err)
+			return "", fmt.Errorf("error parsing stream response: %w", err)
 		}
 
 		if len(streamResp.Choices) > 0 {
 			if streamResp.Choices[0].Delta.ReasoningContent != "" {
-				chunk := streamResp.Choices[0].Delta.ReasoningContent
-				if printerState == chatPrinterContent {
-					fmt.Print("\n\n")
-				}
-				if printerState != chatPrinterReasoning {
-					reasoningFmt.Println("Thinking:")
-				}
-				printerState = chatPrinterReasoning
-				reasoningFmt.Print(chunk)
+				reasoningContent.WriteString(streamResp.Choices[0].Delta.ReasoningContent)
 			}
 			if streamResp.Choices[0].Delta.Content != "" {
-				chunk := streamResp.Choices[0].Delta.Content
-				if printerState == chatPrinterReasoning {
-					fmt.Print("\n\n")
-				}
-				printerState = chatPrinterContent
-				fmt.Print(chunk)
+				responseContent.WriteString(streamResp.Choices[0].Delta.Content)
 			}
 		}
 	}
 
 	if err := scanner.Err(); err != nil {
-		return fmt.Errorf("error reading response stream: %w", err)
+		return "", fmt.Errorf("error reading response stream: %w", err)
 	}
 
-	return nil
+	// Combine reasoning content and response content if both exist
+	var fullResponse strings.Builder
+	if reasoningContent.Len() > 0 {
+		fullResponse.WriteString("\n## 🤔 Thinking\n\n")
+		fullResponse.WriteString(reasoningContent.String())
+		fullResponse.WriteString("\n\n---\n\n")
+	}
+	fullResponse.WriteString(responseContent.String())
+
+	return fullResponse.String(), nil
 }
 
 func (c *Client) Remove(models []string, force bool) (string, error) {

desktop/desktop_test.go

@@ -63,7 +63,7 @@ func TestChatHuggingFaceModel(t *testing.T) {
 		Body:       io.NopCloser(bytes.NewBufferString("data: {\"choices\":[{\"delta\":{\"content\":\"Hello there!\"}}]}\n")),
 	}, nil)
 
-	err := client.Chat("", modelName, prompt, "")
+	_, err := client.Chat("", modelName, prompt, "")
 	assert.NoError(t, err)
 }
 

go.mod

@@ -5,6 +5,7 @@ go 1.24
 toolchain go1.24.4
 
 require (
+	github.com/charmbracelet/glamour v0.10.0
 	github.com/containerd/errdefs v1.0.0
 	github.com/docker/cli v28.3.0+incompatible
 	github.com/docker/cli-docs-tool v0.10.0
@@ -13,7 +14,6 @@ require (
 	github.com/docker/go-units v0.5.0
 	github.com/docker/model-distribution v0.0.0-20250905083217-3f098b3d8058
 	github.com/docker/model-runner v0.0.0-20250911130340-38bb0171c947
-	github.com/fatih/color v1.15.0
 	github.com/google/go-containerregistry v0.20.6
 	github.com/mattn/go-isatty v0.0.20
 	github.com/nxadm/tail v1.4.8
@@ -25,13 +25,23 @@ require (
 	go.opentelemetry.io/otel v1.37.0
 	go.uber.org/mock v0.5.0
 	golang.org/x/sync v0.15.0
+	golang.org/x/term v0.32.0
 )
 
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c // indirect
 	github.com/Microsoft/go-winio v0.6.2 // indirect
 	github.com/StackExchange/wmi v1.2.1 // indirect
+	github.com/alecthomas/chroma/v2 v2.14.0 // indirect
+	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
+	github.com/aymerick/douceur v0.2.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
+	github.com/charmbracelet/colorprofile v0.2.3-0.20250311203215-f60798e515dc // indirect
+	github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834 // indirect
+	github.com/charmbracelet/x/ansi v0.8.0 // indirect
+	github.com/charmbracelet/x/cellbuf v0.0.13 // indirect
+	github.com/charmbracelet/x/exp/slice v0.0.0-20250327172914-2fdc97757edf // indirect
+	github.com/charmbracelet/x/term v0.2.1 // indirect
 	github.com/containerd/containerd/v2 v2.1.3 // indirect
 	github.com/containerd/errdefs/pkg v0.3.0 // indirect
 	github.com/containerd/log v0.1.0 // indirect
@@ -42,6 +52,7 @@ require (
 	github.com/creack/pty v1.1.24 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/distribution/reference v0.6.0 // indirect
+	github.com/dlclark/regexp2 v1.11.0 // indirect
 	github.com/docker/distribution v2.8.3+incompatible // indirect
 	github.com/docker/docker-credential-helpers v0.9.3 // indirect
 	github.com/elastic/go-sysinfo v1.15.3 // indirect
@@ -54,6 +65,7 @@ require (
 	github.com/go-ole/go-ole v1.3.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/google/uuid v1.6.0 // indirect
+	github.com/gorilla/css v1.0.1 // indirect
 	github.com/gorilla/mux v1.8.1 // indirect
 	github.com/gpustack/gguf-parser-go v0.14.1 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.26.1 // indirect
@@ -64,9 +76,10 @@ require (
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/compress v1.18.0 // indirect
 	github.com/kolesnikovae/go-winjob v1.0.0 // indirect
-	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/mattn/go-runewidth v0.0.16 // indirect
 	github.com/mattn/go-shellwords v1.0.12 // indirect
+	github.com/microcosm-cc/bluemonday v1.0.27 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/locker v1.0.1 // indirect
@@ -76,6 +89,8 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
+	github.com/muesli/reflow v0.3.0 // indirect
+	github.com/muesli/termenv v0.16.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.1.1 // indirect
@@ -90,6 +105,9 @@ require (
 	github.com/smallnest/ringbuffer v0.0.0-20241116012123-461381446e3d // indirect
 	github.com/theupdateframework/notary v0.7.1-0.20210315103452-bf96a202a09a // indirect
 	github.com/vbatts/tar-split v0.12.1 // indirect
+	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
+	github.com/yuin/goldmark v1.7.8 // indirect
+	github.com/yuin/goldmark-emoji v1.0.5 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.62.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.34.0 // indirect